Apparatus for use in connection with the refining of petroleum.



0. 1. ROBINSUN.' APPARATUS FOR USE IN CONNECTION WITH THE REFINING 0F PETROLEUM.

APPLIOTION FILED MAR.' 2l, 1907.

Patented Mar. 25, 1913.

,apparatus foruse finmg of such petroleum as 1s obtained from UNITED s'ra'rns rafranr onirica.

CLARENCE I. ROBINSON, OF WEST NEW BRIGHTON, NEW YORK, ASSIGNOR TO STAND- ARD OIL COMPANY, 0F BAYONNE, NEW JERSEY, A CORPORATION OF NEWJERSEY.

APPARATUS FOR USE IN CONNECTION WITH THE REFINING OF PETROLEUM.

1,057,395. it: 'i

Specification of Letters Patent.y

Original application filed August 21, 1903, Serial No. 170,327. Divided and this application filed Marchy 21,.

1907. Serial No. 363,713.

To all l707mm. it may (5071 fern Be it known thatI I, CLARENCE l. ROBIN- soN, a citizen ot the United States, residing at )Vest New Bright-on, in the county of Richmond and State of New York, have invented certain new and useful Improvements in Apparatus for Use in Connection with the Refining of Petroleum, of which improvements the following is a specification.

This invention relates more particularly to in `connection with the rethe oil fields in the State of Texas, near the town of Beaumont, in Jefferson county, the object of the refining being to obtain burning oil (kerosene). Said petroleum is herein referred to as Beaumont oil or Beaumont petroleum tor convenience of reference. The designations are each of them intended .to include'oil of the same or substantially similar character wherever tound or however obtained. For the purposes of this specification, such substantial similarity in character to the oil obtained near Beaumont is suficiently shown for any crude oil by the tact that it responds to each of the two following tests, that is to say, first, the sulfur naturally present therein is given ott (in utilizable proportion) in the form of'hydrogen sulfid when the crude oil is heated to be- I tween about300O F. and about 500o F., and,

second, on distilling the crude.4 oil, with or without cracking,and on collecting by itself the traction coming over between 250 F. and 600O F., more or less, the so collected distillate, after treatment with sulfuric-acid of 66 B. (in however large proportion) and subsequent washing with water and caustic soda lye (all in the knownway) will smoke vbadly when burned in the ordinary petroleum (kerosene) lamps. petroleum l have discovered or invented certain processes by which non-smoking burning petroleum hy the nid of sulfuric acid of eater Astrei1g`;th than the concentrated acid of 66 B. commonly used iii'petrol'eumrefining;

non-smoking burning oil 1 in excess of the For refining such rversely, oil' can he obtained from Beaumonlt-A but the amount of such stronger sul' turic acid to be employed in so obtaining petroleum; and, in order to obtain the requisite supply of acid economically, I have availed myself of, the sulfur naturally present 1n Beaumont petroleum vand also of the sulfur of the acid sludge from the refining operations, ot which acid sludge the quantity produced is naturally larger than in the' refining of Pennsylvania or Lima petroleum, on account of the greater amount'of acid employed in said refining operations. These processes are described and claimed in my applications of August 21, 1903, and March 21, 1907, NOS. 170,326, 170,327 and 363,712 which last is a division and continuation of my saidapplication No. 170,327, having been patenten Marpa, iais.

made in consequence of official .requirement of division. To carry out these processes suitable apparatus is necessary; and in my said applications I have described such apparatus; but it has been held by the Patent @Oiice that my claims on the apparatus must be secured separately from my Vprocess claims. The present application is, theretore, made (in consequence` of such official requirement of division) in order to protect the apparatus which I haveinvented tlor carrying out said processes; and it is filed as a division and continuation of my said application ot August 21, 1903, No. 170,327 and in part also as a continuation of my application of same 'date No. 170,326, the apparatus shown in No. 170,326being included in and forming part of the apparatus sho-wn in No. 170,327.

Portions of ratus can be used separately within the limits of -the present invention. For eX- ample, appropriate portions thereof can be.

utilize the sulfur of such acid sludge, but not the sulfur which is-y naturally present in the crude Beaumont oil. Also portions at least of the apparatus" can be employed `in case there shouldbe other petroleum analogous to Beaumont oil in having sultu r naturally present therein in such form that it can be utilizedsimilarly to that of Beaumontoil, and it should be desired so to in case it should be desired so to my new or'improved appautilize it, or in case it should be desired to utilize the sulfur content of acid sludge from refining petroleum other'than- Beau-v mont oil, whether analogous or not analogous thereto in respect to either or both of the before mentioned tests. Additions to the apparatus, or to portions thereof, can be made; and modificationsfof the apparatus', other than simple omissions and additions, are also permissible within the limits of the invention. For example, in what is considered-the best form of v the apparatus the sulfur'both ofthe crude'oil and of the acid lsludge is converted into sulfuric acid.; butis taken of -any one or more of the claims at.

the end of this specification.

So far as I am aware, naturally present sulfur has never been' recovered in utilizable" form from any crude petroleum, although it has long been known to be. a common con- 'stituent of petroleum and to exist in considerable. proportion i'n some varieties, asv

in 'the oil from the Lima,'Ohi0, and On tario, Canada, fields, for example. l The crude oil from the Pennsylvania fields is nearly free from it. Beaumont crude oil contains, according to my experience, between one and two per cent. of sulfur. The sulfur in Lima or Canadian oil is'not utilizable as I have found that of Beaumont petroleum to be. Torecover it fromcrude Beaumont.

petroleum (or petroleum analogous thereto in. respect to its sulfur content as aforesaid) the same isl best heated' in a suitable still gradually to about 500 F., more or less, and the sulfur-containing gas which is given off during such rise of temperature (all, or

.' part, as mayv be determined) `is collected,

lconveyed away and oxidized to form sulfuric acid. vThis oxidation is effected, rst, rby combustion in hydrogen sulfid burners,

and, second, by subjection 1in lead chambers or'contact v apparatus to the agencies necessary to 'convert sulfur Adioxid' into. sulfuric acid. In this conversion, when it is accomplished in the lead chambers, the sulfur trioxid unites4 with water to form chamberf'acid whichcan thenibe concentrated in any known or suitableway. Should the:

conversion be ,accomplished-in contact apparatus, the sulfur trioxid may. remain free' as'sulfur-ic anhydridorit may be combined' with water, assulfuric acid, more or less Ahydrated as may be desired. Before the sulfuric acid, according to the case.

lIn order to recover the 4sulfur frdm acid sludge to the. best advantage, I have discovered that it is important, first, to heat l. the sludge in bulk (say, in a compact body of several barrels at -a minimum), in order rapidly and economically to obtain a good yield of sulfur dioxid; second, to agitate the sludge during the heating in bulk as aforesaid, in order to avoid foaming; third,

f to raise the temperature Aof the sludge to above 500 F. (to wit, to about 600 E),

in order to get off practically all of the 1 sulfur from the sludge, some of it'coming over as hydrogen sulfid; and, fourth, after condensing the oil vapors therein and s'o effecting their separation and priorV to subject-ing the sulfur dioxid to oxidation for v converting it into sulfuric acid, to expose y`the gas tofheat with access of air, as by passage in Contact with burning sulfur, or sulfur bearing material (as pyrites or hydrogen sulfid) in a state of combustion, in order to burn its combustible constituents and at the same time raise its temperature. It is believed also that the passage of this gas over. burning sulfur (or sulfur bearing material) may be advantageous in other respects. The heating of the gas, in this way, can be effected without expenditure 'of fuel for the'purpose, the products of the combustion of the sulfur or sulfur bearing material being converted into sulfuricy acid along with the gas from the sludge and yielding their surplus heat to the latter.

Between ,the agitator in which the oil to be refined is subjected to sulfuric acid and the acid sludge still in which the/acid sludge is heated there is an acgid sludge l'i e composed bestof a pipe or other con uit and (if necessary or expedient) a pump or pumps but said line may consist of other 4conveying means, as tank cars,`for example, `.whereby the acid sludge can be transported from said agitator to said still. Between the said agitator and the means for making sulfurie acid out of the sulfur'contents of hydrogen suldgiven olf by the crude Beaumont oil and of sulfur dioxid (or sulfur dioxid and hydrogen sulfid) givenv 0H by the vacid .sludge there'is an acid line com-- posed bestof a lpipe or other'conduit and (if necessary or expedient) a pump or pumps; but said acid line may consist of1 other conveyingA means, as tank cars, for examplefor transporting theacid between the said means ffor making sulfuric acid and still has been filled to the desired level it is heated- 'so as gradually to raise the temperature of the stills contents. The gas and vapors as they are formed by the-heat pass over to the condenserc wherein they are cooled to condense the oil vapors. The liquid of condensation flows `into the distillate receiver d'. The gas, including any uncondensed vapor, passes either by the line e to be burned as fuel or otherwise disposed of, or' by the gas line f to be utilized in sulfuric acid making.`

While the temperature of the vapors as they leave the still a is below about 500 F., more or less, the gas from the condenser c consists of about or above 85% hydrogen sulfid (ordinarily, if not always) and is then delivered to gas line f. rlhe temperature is raised to this degree more gradually than in ordinary distillatiom being regulated' with special reference to the production of hydrogen sulid to the best advantage, 'and the distillate being allowed to t-ake care of itself. A l

Should the hydrogen sulfid given off at any time below about 500 F. be found to be unsatisfactory in quantity or quality, it can be sent into ,line e as' long as it may be' so; but in my experience this change of gas line has not been found expedient until about 500 F. is reached. At about or above this degree the gas'should be turned into the line e, so soon as the evolution of hydrogen sulfid fails in quantity or quality, the liner-f-` remaining closed during the rest of the run.

While t-he temperature is rising toward 500 F., the distillate collects in the receiver d until it becomes too s'mokv for utilization without removal of smoky hydrocarbons therefrom beyond what can be accomplished by treatment with. 60 B. acid and redistillation. This has been found in my experience to be when the gravity of the distillate at the worm end (that is, before it enters. the receiver (l.) is about 42 B., more or less, the temperature of the vvapors escaping from the still a being about 400 F., more 1or less.v

The distillate then in the receiver is hereinafter referred to as'the firstburning oil cut.

lt belongs to the lighter' end of the burning oil fraction. It amounts, in my experience, to from five to ten per cent. of the crude oil supplied to still a. The inlet of receiver (l is then closed and that of receiver g is opened, so that the distillate from condenser c will flow into this latter receiver. I This change of receiver has been effected, 1n my experience, before the yield of hydrogen sulid becomes unsatisfactory; so that for a time after the change-of receivers the lheating of' the still a is reglllatedwith special reference to the evolution of hydro n suld. Afterward the heat of still, a; 1s regulated (as customary) with special reference to the distillate to be obtained.

The distillation is carried on with crackingwhich lcommences (in my experience) when the temperature of the liquid oil in the still a is about 600 F., more or less, the

distillate in the two receivers d and g then amounting to about 40%, more or less, of

the crude oilV suppliedto the said still a...

The distillation is. continued as long as it is safe to do so, say, till the distillate in said two receivers amounts to about 85% of said crude oil. The oil in receiver g is herein termed the cracked oil distillate; although a large percentage is composed of uncracked products.

It is customary to have a receiver into which thedistillate vcan be turned whenever it becomes undesirable in quality, the result of something accidental; 'the receiver 7L is provided for such purpose. When necessary, its inlet can be opened, those of the receivers d and g being closed. Any one of the three receivers could be used for this purpose, the other two serving to collectthe first burning oil cut and the cracked oil distillate,.respectively. After the completion of arm the crude oil still a can be emptied throughythe tar line j orv in any suitable way, preparatory to refill-ing with crude oil for a new run.

The cracked oil distillate from receiver g is delivered by pump 1^, through line s, into distillate still 7c, wherein it is distilled to separate the burning'oil from the heavier fraction. The vapors pass over to the condenser Z, where they are reduced to the liquid state, any uncondensed products escaping by the line m, to be used as fuel or as may be desired. The distillate is collected in the receiver n until it becomes too smoky to be used in burning oil without removal f' of the smoky hydrocarbons beyond what can be effected by treatment with 66 B. acid and redistillation. 'In my experience, this occurs when the oil from the worm end about 42 B., the teomperature of the vapors from the still c being about 420 F., more or less, and the distillate in receiver n being about eight per cent. of the crude oil supplied to still a. This port-ion of distillate is hereinafter referred to as the second burning oil cut. Like the first burning oil cut, it belongs to the lighter end of the burning oil fraction. After it has been collected, the

oilfrom condenser Z is run into receiver 7) so long as the distillate from the worin end` lll@ can be made non-smoking by treatment with a moderate amount` of 98% acid and distillation of the so-treated oil'. In my experience, the distillate (hereinafter termed the third burning oil cut) can be thus collected in the receiver p until it amounts to about of the crude oil supplied to the still a, the gravity of the oil at the worm end being about- 81 B., more or less, and the temperature of the vapors escaping from the distillate still k being about 5500 F., more or less.

The residuum in the distillate still 73 is then withdrawn thro-ugh tar line g, leaving the still empty for another run. This nextrun may be made on another lot of cracked oil distillate from receiver g, or it.- may be a distillation after treatment with acid of one or 'other of the burning oil cuts or of a mixture of said cuts; for as shown the one still 7c serves for both distillations'. It is to be understood, however, without further statement, that where one still, agitator or other vessel is shown, in practice as many of such vessels as desired can be used, andthat it is not material to distill or to collect different oils, cr to treat different oils with acid in the same vessels.

4The first and second burning oil cuts are treated with ordinary concentrated acid either separately or mixed together, as may be preferred. They are delivered from their respective receivers Z and a by the pump r through a branch of the oil line s to the agitator t. Here the oil is agitated as customary in the sulfuric acid treatment with acid of (36o B.; and, after settling and drawing off the acid slud-ge through pipe u into sludge tank w, .the oil is washed repeatedly with water and then withv a solution of caustic alkali. The water .and alkaline solution can be removed (after proper settling in each case) through the draw-off w. In my experience, about ten pounds of 66 B. acid to a barrel of the distillate treatedis sufficient.

The treated oil is delivered by pump y lthrough part of oil line s into distillate still 7s and is subjected to an incomplete distillation therein, that is to say,'it is distilled so long as the oil from the worm end is satisfactory.v The-oil from condenser Z during this distillation collects in the receiver a. The residuum in still lc, amounting, in my experience, to between ten and'twenty per cent. of the charge of said still 7c, is then run off through the tar line g, leaving the still 7c ready for the next run.

The -third burning oil cut is pumped from receiver p into agitator t and is there agitated with 98% of acid in moderate amount for about an hour. In this time, according to my experience, the effect ofthe acid will be exhausted. y The acid in two portions and may be in all about two pounds, more or less, of acid to each gallon vthe second burning oil cut.

shouldl be './applied of the oil treated, namely, of the third burn- The oil should have a temperaing oil cut. ture of about 90 F., more or less, at the beginning of the treatment. The acid sludge is drawn off into the tank w, and the treated oil is washed repeatedly with water and afterward with a solutito-n of caustic alkali as4 in the ordinary sulfuric acid treatment.

The treatment with 98% acid greatly improves the oil; but it will still contain an excess of smoky hydrocarbons, as well as acid compounds which would cause the lamp wick to be charred were the oil without further refining burned inA a lamp. The treat- I ed o-il is, therefore, deliveredby pump y, through oil line s, into distillate still t: 'and subjected-to an incomplete distillation, that is, a distillation so long as the collected distill ate constituting the third burning oil cut, after mixture with the light ends (first and second burnin oil cuts) furnishes a product which as a w ole shows either by burning4 in a lamp or by the refractometer the proper freedom from smoky hydrocarbons. According to my experience, the distillation would best not be continued after the oil from the worm end reaches 2,9?0 B. or somewhat lighter (say, between 30 B. and 31 B.) if the still should be running slowly.

The third burning oil cut is collected in the receiver p, or in the receiver n, if desired.` The residuum, amounting, in my experience, to about ten per cent., more or less, of the treated o-il charged into the still 7c, will contain the worst (smokiest) portions of the oil. It is run off by the tar line g.

By the 'preceding operations there willhave been obtained one, two or three lots of oil, according to the collec-tion in one, two or three-receivers of the distillates from the incomplete distillation of thethree burning oil cuts. Therefining of said distillates lis finished by subjecting them, separately or two or mo-re of them in admixture, to treatment in the usual way with a small quantity of 66 B. acid in the agitator t; and 'the finished oil is thence run by line 2 into the tank 2, wherein the oil from different .cuts can be mixed, if not already in admixture.

In my experience, Beaumont crude oil Acontains such a small percentage of Vlight products that steam stilling is'not necessary for low test burning oil (kerosene); but if it should be desired 'to increase the fire test, the finished oil, or one or bot-h the lighter burning oil cuts, may be steam stilled to bring the product to thev desired test. According to my experience, itshould sufiice to steam still the finished oil from Either or both of the finished light' ends could be mixed other aeriformuid therein, is conveyed by the gas line f to a storage gascmeter 3, from which it is supplied to the burner 4, wherein both it and. other combustible substances present are burned, the hydrogen suld being converted therebyinto sulfur dioxid and water. These may lboth vbe delivered through gas line into the lead chamber 6 f the acid sludge stil-110 until the latter is filled to the desired level (say, 200 barrels of acid sludge in a still of 500 barrels capacity). The still may be of iron and be heated by fire in any known or suitableway.

' As shownit is provided with a rotary stirrer 11, in order to check foaming. After charging the still is heated so as to keep up a good delivery of sulfur dioxid, say, about 2,500 cubic feet, more or" less, per hour.

The evolution of gas begins at about 220o F. (temperature 0f the liquid), and at about 600 F0. should be practically complete, only line f, otherwise than for the preparation of coke remaining in the still.

The gas and vapors from still 10 (which may be of iron) are passed through the condenser 12 (which should have a lead Worm) making sulfuric, acid, should ning of the decomposition, on account of the in order to separate. the small amount of oil vapors carried over with the sulfur dioxid. The sulfur dioxid then passes by gas line13 to a storage gasometer lll, from which (after being heated) it is sent either into tower 7 or chamber 6, in order to be converted into sulfuric acid. At 13 is in-A dicated the beginning of a valved branch gas line Lfor switching out the gas, instead ofallowlng, it to pass to the apparatus for it be desiredat any time todo so. Occasion for this would be most apt to arise, if at-` all, at the beginlar er proportion in some cases of hydro'- car ons then present in the gas. The gas, when switched out, can be used as fuel orbe otherwise4 disposed of, as the manufacturer may determine. l ,Y

Toward the Iend of the operation` in removing the last rportion of sulfur from the sludge, some hydrogen suld comes over..

To convert this into sulfur dioxid (and water) ,the ygas may be passed through the burner 4 on its way to' the lead chamber 6.

As the. gas, from bondenser 12 is `cold throughoutr the operation, it shouldbe heatedbefore-itis admitted into tower Z or receiver 15.

the still 10 preparatory to the next run) can ample) in which combustion yielding sulfur Such passage insures dioxid is going on. "also-the combustion of any small quantities of hydrocarbons which may be present in the gas.' All the sulfur dioxid from such burner Would pass into/the sulfuric-acidmaking apparatus.

The oil from co-ndenser 12 runs into the It and the coke (removed from be used as fuel or otherwise disposed of.

, The dilute sulfuric acid from ulehadv 22 into the agitator 't as above described.`

The acid' of 660' B. can be obtained' from another portion of the same dilute acidand be delivered Ain the same way to the said agitator.

' Should it be so desired, all, or any part,

of the acid produbed can be sold in any de-y sired kind or degree of concentration. Should it be desired to utilize the sulfurcontaining gas givenoffI from Beaumont or analogous crudeoil and collected according to the preceding description through the sulfuric acid, it could be done by'V subjecting the said gas to any known `or suitable procedure for the utilization of hydrogen sulfid. 'I believe I am the lirst to collect such gas for the utilization ofthe hydrogen suld therein. So also the gas from the distillation of the acid sludge could be subjected to any `known or suitable procedure for the utilization of sulfur'dioxid'.

The expression means for utilizing the sulfur content in those of the hereinafter such appurtenances and additions as may be 'necessary for making sulfuric acid Iby' specifiedfin making sulfuric acid; and by still further extension'. said expression includes any known or suitable means in general for utilizing such sulfur content, the same comprising not, only means for making sulfuric acid therefrom, but also means for .forming sulte and bisulfite salts, sulfurous -acid solutions, elemental sulfur, and so on,

from such sulfur content.

Eachvof the expressions 5 still as specified and box like still as specified written claims in which it occurs designates primarily one or more lead chambers, withy -means primarily an ac'id sludge still, but it includes also-a still for heating an oily liquid in general for evolving therefrom gas which shall contain sulfur in the form of hydrogensulid or of sulfur dioxid, or-

of both, in utilizable amount, 'acid sludge from pet-roleum refining operations being such li uid, but not necessarily the only such. rude Beaumont oil is another such liquid; and there are no doubt others. The cheese Ibox still and the horizontally disposed cylinder still of the oil retiner are both included in4 theexpression box like, which, moreover, is'not necessarily restricted to these forms.

I claim herein as my invention or discovery:

1. The combination withv a crude oil still provided with a crude oil charging line and adapted to keep up a good delivery of aeriform products with gradual heating of the stills contents, of a condenser,'a hydrogen sulfid burner, means for converting sulf ur dioxid into sulfuric acid, a gas line leading from said still rst through said condenser and thenthrough said burner to 'said means, a gas line communicating with the vapor space of said still and leading elsewhere than t-o said means, and appliances whereby. the aeriform. products evolvedin4 saidv still can be sent through one gas line -to said means in order to form sulfuric acid therefrom or can be Iotherwise disposed of through the other of saidv gas lines, substantially as described.

2. The combination with a crude oil still provided with a crude oil charging line and adapted to keep up a good delivery of aeriform products with gradual heating of the stills contents, of a condenser, a hydrogen suld burner, means for utilizing the sulfur content of sulfur dioxid, a gas line leading from said stilly first through said condenser and then through said burner to said means, a gas line communicating with the vapor space ofsaid still and leading elsewhere than yto said means, and appliances whereby' the aeriform products evolved in said still can be sent thrpugh one'gas line to said means in order to utilize the sulfur content of the sulfur dioxid therein .or can be otherwise disposed of through the other of said gas lines, substantially as described.4 v

3. The combination with a crude o il still provided with a crude oil charging line and adapted to keep u' a good delivery of aeriform products with gradual heating of, thestills contents, of a condenser, means vfor utilizing the sulfur content of h drogen sulfid, a gas line leading fromsai f -still through lsaid condenser to means,- a

branch line communicating fwith. ;the vaporl space of saidfstill and lead'in'gfelsewhere than to said-means, and appliances'whereby -ing off and conveying away in a liquid state the residual contents of said still, of acondescribed.

the aeriform products evolved in said still can be sentfthrough one'gas line to 4said means in'order to utilize the sulfur content of the hydrogen sulfid therein' or can be otherwise disposed of through the other of said gas lines, substantially as described.

4. The combination with a crude oil still adapted to keep up a good delivery of aeriform products with gradual heating of the stills contents and provided with a crude oil charging line and also with'a line for drawing oif and conveying away in a liquid state the residual contents of said still, of a condenser, a hydrogen suld burner, means for converting sulfur dioXid into sulfuric acid, and a gas line leading from said still first through said condenser andi then through said burner .to said means, substantially'as described.

5. The combinationl with a crude oil still adapted to keep up a good delivery of aeriform products with gradual heating ofthe stills contents and provided with a crude oil charging line and alsof with a line for ,drawdenser, a hydrogen sulid burner, means for utilizing -the sulfur content of sulfur dioxid, and a gas line leading from said still first through said condenser and then through 95 said burner to said means, substantially as 6. The combination with a crude oil stillv adapted to keep up a good delivery of aeriform products with gradual heating of the stills contents and provided with a crude oil charging line and also with a line fordrawing 0E and conveying awayin a liquid state the residual contents ofsaid still, of a condenser, means for utilizing the sulfur content of hydrogen sulid, anda gas line leading from said ystill through said condenser to said means, substantially as described.

7. The combination with -a box like acid sludgestill arranged to hold several barrels 11o of sludge at aminimum and to keep upa good delivery -of aeriform products with gradual heating of the sludge and consequently. without carrying sludge over into the vapor outlet to clog the same, of means forpurifying sulfur dloXid. and converting it finto sulfuric acid, and a'gas line leading from said still to said means, substantially as described. f

y8. The combination. with a box like acid sludge still arranged to hold several barrels of sludge at a mlnimum and tokeep up a good delivery of aeriform products with gradual heating of the sludge and consequently without carrying sludge 'over into 125 verting'sulfur dioxidI in to sulfuric acid, and 13 0` a gas line leading from said still iirst through `said condenser and then through 'said burner to said sulfur dioxid converting means, substantially as described.

9; The combination with a box like acid sludge still arranged to hold several barrels A of sludge Aat a minimum and to keep up a from said still through said condenser to -said means, and a burner located in said gas line intermediate said condenser and said converting means and providedwith instrumentalities for supplying additional sulfur thereto in a combustible form, substantially as described. j

10.' The combination with a box like acid sludge still arranged to hold several barrels of sludge at a minimum and to keep up a good delivery of aeriform products with gradual heating of the sludge and consequently vwithout carrying sludge over into the vapor outlet to clog the same, of means for purifying sulfur dioxid and utilizing its sulfur content, and a gas line leading from said still to said means, substantially as described. y

11. The combination with a boit like acid sludge still arranged to `hold several barrels of sludge at a minimum and to keep up al good delivery of aeriform products with gradual heating of the sludge and consequently without carrying sludge over into the vapor out-let to clog the same, of a stirrer in said still adapted by its agitation of the sludge to lessen the foaming. of the latter, means for purifying sulfur dioXid and utilizing its sulfur content, and a gas line leadi ing from said still to said means, substantially as described.

l2. The combination with stills, oneV of them being a crude oil still adapted to keep up a good delivery of aeriformproducts with gradual heating of the stills contents and provided with a crude oil charging line and also with a line for drawing off and conveying away in a liquid state the residual contents of said still, and another of said stills being a box like acid sludge still arranged to hold several barrels of sludge at a minimum alld to keep up a good delivery of aeriform products with gradual heating of 'the sludge and consequently without carrying sludge over into the vapor outlet to clog the same, and provided with a stirrer which is adapted by its agitation vof the sludge to lessen the foaming of the latter, of condenser-s, a hydrogen sulfd burner, means for converting sulfur dioXidinto sulfuric acid, a gas line leading from each of said stills first through a condenser and then through said burner to said means, a gas line communicating with the vapor space of said crude oil still and leading elsewhere than to said means, and appliances whereby the aeriform products evolved in said crude oill still can'be sent through one gas line to said means in order to form sulfuric acid therefrom in connection with the aeriformproducts evolved in said acid sludge still or can be disposed of otherwise through ,the gas line leading elsewhere than to said means, substantially as described.

In testimony whereof I aifiX my signature, in presence of two witnesses. f

CLARENCE I. ROBINSON.

Witnesses:

LEE TOADVINE, A.1 I".r ARNOLD. 

